[network] move socket_bench_server to dev-dependencies
[network] move socket_bench_server to dev-dependencies

Closes: #1221
Approved by: metajack

aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,libra/libra,libra/libra,aptos-labs/aptos-core,aptos-labs/aptos-core,libra/libra,libra/libra,libra/libra,aptos-labs/aptos-core